1. What is the most important
fact in all of science?
Come up with your own
suggestion

2. Atoms
Atoms an Heat Lesson 3
Year 11 Physics

4. Richard Feynman
1918 - 1988
Six easy pieces
―All things are made
of atoms—little
particles that move
around in perpetual
motion, attracting
each other when they
are a little distance
apart, but repelling
upon being squeezed
into one another. ―

5. ―Fiction Physics‖
Ernst Mach
1838 - 1916
―Atoms are things which can never be seen or
touched and only exist in our imaginations‖
―Have you seen one?‖
How can, one generation after scientists doubt
their existence, atoms be considered the most
important fact in all of science?

6. What is the atomic model?
It is not just that everything is made out of
tiny spheres (balls).
There are different types of balls; atoms,
molecules and ions.
The balls are moving.
It is called particle theory or kinetic theory
Atoms intro

7. Why do scientists think they exist?
Example of a allegorical model
First ―used‖ by John Dalton to explain the
ratios of products produced in chemical
reactions.
As a model it explains and predicts most
of material science (chemistry) and tons of
physics.
It works!

8. Any evidence?
It is not possible to
―see‖ atoms. They
are smaller than the
wavelength of light.
There is other
evidence.
1. Brownian motion
2. Gas diffusion
Have you
seen
one?
Can a crime be
prosecuted without
witnesses?

9. Atom images
We can now produce
images of atoms using
scanning tunnelling
microscopes (STM)

10. Using kinetic theory
Success Criteria…
Use the ideas of kinetic theory to explain
Brownian Motion or Gas Diffusion.
Your explanation must
- include diagrams
- describe the macroscopic event and
why it is strange
- use the idea of moving invisible
microscopic particles

11. Diffusion in liquids
Watch the video clip
Diffusion in liquids
Success Criteria
Explain the results of the experiment.
Use the ideas of kinetic theory
Use diagrams

12. Demonstrate your learning – Dear Mr Mach
Write a letter to Ernst Mach
The purpose is to convince him that atoms
exist.
They are not just a useful model
Success Criteria
Letter has an introduction
Use examples and evidence
Letter has a conclusion
Uses key words precisely